Tibial Plateau Angle Changes following Repair of Salter-Harris Type 1 and 2 Fractures in Dogs.

Objective:  To determine (1) whether the tibial plateau angle (TPA) in dogs with Salter-Harris type 1 (SH-1) or type 2 (SH-2) fractures of the proximal tibial physis significantly decreases in the time between diagnosis and reevaluation following surgical repair and (2) whether the method of surgical repair influences the change in TPA over time.

Study design:  This study was a retrospective study. Medical records from 2017 to 2022 were reviewed to identify dogs with SH-1 or SH-2 fractures of the proximal tibial physis that had undergone surgical repair with Kirschner wires (K-wires), with or without a tibial tuberosity tension band. The TPA of the affected limb was measured by four investigators on radiographs taken prior to surgery, immediately postoperatively and at 4-8 weeks follow-up, with the average values recorded.

Results:  A total of 32 dogs, 22 fractures repaired with K-wires and a tension band, and 10 with K-wires only. There was a mean decrease in TPA from injury to first reevaluation of 5.89 degrees (p < 0.001) and from immediately postoperatively to first reevaluation of 2.2 degrees (p = 0.018); however, no significant decrease in TPA was observed when comparing fractures repaired with or without a tension band.

Conclusion:  The TPA of dogs with SH-1 and SH-2 fractures of the proximal tibial physis decreased in the reevaluation interim following repair with K-wires with or without a tension band. Despite initial imperfect reduction, the risk of cranial cruciate ligament rupture may not be increased, potentially reducing the need for additional surgery if high TPA is observed postoperatively. This study was overrepresented by small breeds, and future studies on large and giant breeds with extended follow-up would be indicated.